code: def test_ring_graph():
      """Second order centrality: ring graph, as defined in paper"""
      G = nx.cycle_graph(5)
      b_answer = {0: 4.472, 1: 4.472, 2: 4.472, 3: 4.472, 4: 4.472}
  
      b = nx.second_order_centrality(G)
  
      for n in sorted(G):
          assert b[n] == pytest.approx(b_answer[n], abs=1e-2)
  
file_path: networkx/networkx/algorithms/centrality/tests/test_second_order_centrality.py
imports: import pytest
  import networkx
label_desc: Use image node_id 8 for calling a global function with example usage: test_ring_graph() without return types